Russian synchronized swimming pair Anastasia Davydova and Anastasia Ermakova retained the Olympic duet title with a near-perfect performance at the Water Cube here on Wednesday.

The Russian pair scissor-kicked their way to a lively piece of Norwegian play music in the free routine final, scoring eight full 10 marks and two 9.9 points. They carried a top score of 49.334 points from Monday's technical routine to total 99.251 points.

Spanish veteran Gemma Mengual and Andrea Fuentes won the silver with 98.334 points, and Japanese duo Saho Harada and Emiko Suzuki took the bronze with 97.167 points. Chinese twins Jiang Tingting and Jiang Wenwen finished fourth with 96.334 points.

The two Anastasias, who paired up since 1998,  have taken home gold at every international competitions since 2002.  With a second Olympic gold medal, they reinforced their leading position in the sport.

The Chinese twins were expected to medal in the duet competition, but failed after making an error towards the end. "Of course there were regrets. We had aimed to win a medal," their coach Masayo Imura said.

"I think they only gave about 93 percent of their performance level," she said, "and coming into the final as the fourth also made it difficult for them to catch up with the stronger performers."

"Now we will make another efforts in the team competition to get a medal," she added.